Ayesha

If beams are fixed, you have moment connection. The frame has lateral rigidity. If beams are pinned, all the lateral load would need to go to a bracing system or shear walls. Providing fixity increases stiffness and also allows you to use smaller sections to satisfy gravity deflection limits apart from lateral stuff.

Time period is still based on uncracked properties as that would result in a shorter period ; more stiffness; higher seismic load. There are multiple very rigorous discussion on the forum about time period. Below is one thread, you can search others.

This is not a very common error and I would suggest contacting CSI Help for this if you are using licensed version of ETABS.

The seismic data for IBC for major cities of Pakistan is provided in this thread that I posted above.

Calculate your base shear.. delete everything from the model except for shear wall and apply the seismic load manually on the wall. That is one way to do it.

You should contact CSI Help as this looks like a very weird error. Shouldn't ignore. Sharpen the pencil to see if you can take some conservatism out of your loads and reduce the seismic loads and improve your results but otherwise go with the results 'as-is'.

Basis for release depends on beam end reinforcement. If no top reinforcement (-ve moment can't develop) the beam will crack on top and act as simply supported beam. You can release end moment that and design as simply supported beam.

Normally, we run all load combinations and then in result summary see which load combo is governing and check that one.

You should use IBC with ACI as UBC is not compatible. If you still want to use UBC, this is grey area and engineering judgement should be used. Discuss with the people in your office and pick something conservative. There are two approaches. Either you design based on Envelope (Consider the max of all forces, Fx, Fy, Fz, Mx, My, Mz) and design for that. Or you can each load combination one by one. You can develop an excel macro to do that.

I am not an expert on temperature loading so can't comment further.

Q1. 100 psf. This comes from Building Code so double check the code you are following. Q2. See the discussions posted below.

I think diaphragm assignment will cancel out opposite forces but still there will be pass through forces that will be required for design. In general, for thermal loads, it all depends how you apply your thermal loads. Say if you have a top roof slab where the outer side is exposed to sun and inner side is exposed to air conditioning, the temperature variation will produce bending moment in the slab.

@Badar (BAZ) is totally correct. I will just add that some people prefer manual Load Combinations to address vertical seismic effects which you can also do with Auto, if you specify the correct parameters. See the thread below. https://www.sepakistan.com/topic/1307-etabs-load-combinations/

Diaphragms are by default area objects. You can select beams but it would be assigned to slab.

I would suggest that you network in UK and try to get in some company there instead of looking at Pakistan. I know some friends who went abroad and were able to land something based on their networking skills. Your starting point is your University Alumni Network. Good luck.

You can put timer or plates under scaffolding to reduce damage. Best thing would be to speak with local vendors or agents that deal with mix design and also with scaffolding people. They might be familiar with something that they have used before to address your concern.

I think there is some guidance in ACI code 10.15 (ACI 2002 or around that time) f'c of column <= 1.4(f'c of floor). I don't know the reference number is newer ACI. Also check the commentary for 10.15 as I don't remember exactly.

You cann't just assume. This is very dangerous. You cannot design masonry in ETABS because masonry behaviour is different. Since you are a fresh engineer, I would suggest that you spend sometime understanding difference between masonry and concrete behavior. Read articles from internet and search.

There are similar discussions on the forum. Please check and post updated questions if still unanswered. Raft Edge or Corners Overstressed: https://www.sepakistan.com/topic/3106-raft-edges-and-corners-overstressed/?tab=comments#comment-10121 High Soil Bearing Pressure under Raft: https://www.sepakistan.com/topic/2918-high-soil-bearing-pressure-under-raft/?tab=comments#comment-9375 Calculating Soil Spring: https://www.sepakistan.com/topic/1303-spring-support-modulus-of-subgrade-reaction/?tab=comments#comment-3548 Numerous Questions on Raft Design: https://www.sepakistan.com/topic/1440-raft-design-for-a-2-basementg24-story-building/?hl=raft Minimum Thickness of Foundation: https://www.sepakistan.com/topic/160-minimum-thickness-of-footing/?hl=raft

What is the basis for this? Why E is not divided by 2.5 or 3? Masonry has no to limited, out of plate strength. How are you making sure, your modelling approach is different from modelling a shear wall..?

Sundass, The first thing will be to confirm if the loads are applied correctly and modelling is done correctly. That can be confirmed on your end. For loads, should first see which load combination is governing. Say 0.9*D + 1.5Live is governing. You can manually calculate the dead load, and the live load. Check the reactions of basic load case of live and dead to your manual numbers to see if they match. Once you have done it then comes the modelling. For modelling, the easiest thing would be to confirm deformed shape for each load case in the governing load combination and observing if it makes sense. Another thing that you can do is to use a spreadsheet or manual calc for column design or another software like PCA Col and check ETABS results. It could be, be it requires checking and making sure there are no mistakes. Basic checking is required.

Could be.

Very strange. Is this copy of ETABS licensed? Post your error log.

It can be any kind. You need to meet architectural requirements. You can make two different custom sections in section designer. Use one section for bottom and other for the rest. I believe Section Designer can handle openings. If not, you can draw walls. I would suggest you to check ETABS Watch and Learn on Section Designer.

You need to tell the client what is required. Since concrete is heavier than water, one way would be to increase the basement thickness till you achieve enter counter dead weight or install piles and design basement floor as raft so it is anchored to ground.